The original sandwich, which clocks in at 1030 calories before piling on the seafood, now comes with the option to include a wild-caught Alaskan Pollock filet. Customers can get the fish-topped version by asking for the sandwich "Denali-style," which references the mountain in Alaska where the fish originates.

The original Meat Mountain was first served after customers reportedly viewed a promotional poster showing the chain's wide variety of meats available and wondered if they could get them all together.

“People started coming in and asking, ‘can I have that?’” Christopher Fuller, Arby’s vice president of brand and corporate communications told the Washington Post in 2014 when the Meat Mountain first hit the market. Shortly after, the sandwich that’s too big to fit into the clamshell packaging, started to become a viral hit.

But some fast food fans aren't sure that proteins from the land, sky and sea all belong in the same meal.

The Arby’s menu isn’t just getting fishy. The chain also recently added a Chicago-style beef dip to its “Big City Sandwiches” selection, which offers regionally styled meals like a Fire-Roasted Philly and New York Reuben.

The Meat Mountain (with fish) is available now through the end of March.